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This study examines the characteristics of volatile organic compounds (VOCs) and their major emission sources at the Bulgwang site in Seoul, Korea. The annual levels of VOCs (96.2–121.1 ppb C) have shown a decreasing trend from 2004 to 2008. The most abundant component in Seoul was toluene, which accounted for over 23.5 % of the total VOCs on the parts per billion on a carbon basis, and the portions of alkanes with two to six carbons constituted the largest major lumped group, ranging from 40.1 to 48.4 % (45.3 ± 3.7 %) of the total VOCs. Major components of the solvent (toluene, m/ p-xylene, o-xylene, and ethylbenzene) showed high in daytime and summer and low in nighttime and winter due mainly to the variation of the ambient temperature. The species mostly emitted from gasoline vapor ( i/ n-butane, i/ n-pentane, n-hexane, and 2-methylpentane) and vehicular exhaust (ethylene, acetylene, and benzene) showed bimodal peaks in the diurnal variation around the commuting hours because of the high traffic volume. For the 14 out of 15 highest concentration species, the weekend effect was only evident on Sundays because of the stepwise implementation of the 5-day work-week system. Principal components analysis (PCA) was applied in order to identify the sources of the 15 highest concentration VOCs and, as a result, three principal components such as gasoline vapor (48.9 %), vehicular exhaust (17.9 %), and evaporation of solvents (9.8 %) were obtained to explain a total of 76.6 % of the data variance. Most influential contributing sources at the sampling site were traffic-related ones although the use of solvent was the dominant emission source based on the official emission inventory. [ABSTRACT FROM AUTHOR]

The characteristics of volatile organic compounds (VOCs) and their annual trends in Seoul, Korea were investigated, with their optimal control strategy suggested. The annual concentration of VOCs (96.2-121.1 ppbC) has shown a decreasing trend from 2004 to 2008, suggesting the control strategy via the 'Special Measures for Metropolitan Air Quality Improvement,' which was implemented in 2005, has been successful. The contributions of individual VOC to the production of ambient ozone and secondary organic aerosol (SOA) are discussed to assess the adequacy of current control strategies. The contribution of aromatics (C6-C10) to the production of ozone accounted for 38.7-46.3 % of the total ozone production, followed by low carbon alkanes (C2-C6) (27.0-35.9 %). The total SOA formation potential of VOCs was found to range from 2.5 to 3.5 μg m, mainly as a result of aromatics (C6-C10) (over 85 %). Considering the contributions from ozone and SOA production, it was concluded that solvent use was the most important emission source, followed by vehicle exhaust emissions. Thus, the current emission control strategy focused on these two emission sources is appropriate to reduce the VOCs related pollution level of the Seoul Metropolitan Region. Still, an additional control strategy, such as controlling the emissions from meat cooking, which is an emission source of high carbon alkanes (C7-C10), needs to be considered to further reduce the VOCs related pollution level in Seoul. [ABSTRACT FROM AUTHOR]

Study design:Prospective, cross-sectional study, based on cases of spinal cord injury (SCI).Setting:Three outpatient medical departments in Seoul, Korea.Objectives:To assess depressive symptoms in patients on clean intermittent catheterization after SCI.Methods:In total, 102 subjects (68 males and 34 females, mean age 39.5 with a range of 18–75 years) were included in the primary analysis. A control group of 110 was selected from the routine health checkup. All subjects completed the Beck Depression Inventory (BDI).Results:For patients and controls, the average total BDI scores were 20.3±1.0 and 11.4±0.5, respectively (P<0.001). With regard to severity of depression among patient groups, three (3.0%) reported normal; four (3.9%) reported mild to moderate depression; 24 (23.5%) reported moderate to severe depression; and 71 (69.6%) reported severe depression. On the multivariate logistic regression analysis, a positive association with the risk of depression was observed in gender and type of catheterization. Female patients had a 3.8-fold higher risk (odds ratio (OR) 13.83; 95% confidence interval (CI) 1.42–10.31; P=0.008) of depression than male patients. In the same model, patients who were unable to perform catheterization independently had a 4.6-fold higher risk (OR 4.62; 95% CI 1.67–12.81, P=0.003) of depression than those who were able to perform self-catheterization.Conclusions:The results demonstrate that the patients with neurogenic bladder secondary to SCI have higher degrees of depression than normal population. In addition, our findings also suggest that depression is closely related to gender and patient's ability to perform self-catheterization.Spinal Cord (2006) 44, 757–762. doi:10.1038/sj.sc.3101903; published online 24 January 2006 [ABSTRACT FROM AUTHOR]